The spade confirms the myth. That is the traditional marriage of legend and archaeology.

For centuries - actually millennia - Troy was thought to be the mere creation of a blind poet, who himself may not have existed. But, in 1870 Heinrich Schliemann put his spade into the soil of western Turkey and found not only one but many Troys. Just six years later, he unearthed the gold of the Mycenaeans who ruled Bronze Age Greece 3500 years ago. The Homeric era was real.

In Egypt, Imhotep had long been worshipped as a god of healing and architecture, a far cry from his cinematic role in "Return of the Mummy." The real mythical Imhotep was architect to Pharaoh Djoser, who was buried in the famous pyramid at Sakkara. Or so the legend went, until Imhotep's name was found in Djoser's tomb. Imhotep was real, not a myth.

Careful excavation of the bones and cartridges at the Little Bighorn site has confirmed some battle stories and disproved others, in the endless search for the real story of Custer's last stand. The excavation of mass graves has confirmed stories of the Black Death in England and of Saddam's atrocities in Iraq.

Excavations at Traveler's Rest, a spot where the Lewis and Clark Expedition camped and recuperated, have found a pit with a high level of mercury. The surrounding soils have no mercury. The pit is almost certainly the expedition's latrine and the mercury is almost certainly from the pills administered to the men to treat syphilis.

Earlier in the expedition, Lewis and Clark had stopped for the winter at the Mandan villages. Within days of arriving among the Mandans, the journals report an outbreak of syphilis, a disease whose usual incubations period is three weeks. The expedition had been in the Arikara villages just three weeks before arriving among the Mandans. A reasonable conclusion is that this episode of syphilis reflected disease caught among the Arikaras.

Many studies have shown that syphilis alters many anatomical structures, including the bones. Therefore, the bones of early 19th century Arikara Indians should also bear these syphilitic stigmata. But they do not!

How can this be? Why does the evidence of the spade - the carefully studied bones - not confirm the clearly recorded observations of the two famous captains, both meticulous diarists? The attempt to unravel the mystery will lead us to several subsidiary and equally vital questions:

Medical understanding of venereal disease in 1804.

Evidence of venereal disease among the Arikaras.

Evidence that the Arikaras were willing to share their sexual favors (and illnesses) with visitors.

Evidence for absence of venereal disease in the Lewis and Clark Expedition before arriving at the Arikara villages.

Possible errors in the Lewis and Clark journals.

The current science of paleopathology, or how to read the bones.

Limitations in the science of identifying disease in bones

A careful consideration of all these questions may enable us to answer The Mystery of the Bones.